With his hand over his heart, President Bush stood among rows of white tombstones in Arlington National Cemetery yesterday to honor “the 24 million Americans who strengthen our nation with their example of service and sacrifice.”

“Most of these markers stand over graves of Americans who came home to enjoy the peace they earned,” Bush said yesterday.

“Too many stand over the graves of those who gave their lives to protect that peace. This day is dedicated to all who answered the call to service – whether they live in honor among us or sleep in valor beneath this sacred ground.”

Surrounded by soldiers standing at attention, their rifles firmly gripped in their hands, Bush laid a wreath at the Tomb of the Unknowns.

Cannons fired a 21-gun salute as the presidential motorcade drove past the rows of headstones.

“They have brought down tyrants. They have liberated two nations. They have helped bring freedom to more than 50 million people,” Bush said, alluding to Iraq and Afghanistan.

“Through their sacrifice, they are making this nation safer and more secure – and they are earning the proud title of veteran.”

Buglers played “Taps” to honor those whom Bush called “our nation’s finest citizens.”

Things were considerably more festive for the president’s incoming secretary of Defense, Robert Gates.

Just a few days after he was tapped for the job, the new defense secretary and outgoing president of Texas A&M enjoyed a football game between his school and Nebraska.

Cameras caught Gates – who will help guide the war in Iraq – in a raucous line dance with members of the college’s corps of cadets.

With their arms draped over one another, Gates and the uniformed cadets shouted out the school song just before kickoff.

Meanwhile, veterans of conflicts in Europe, Asia and the Middle East marched up Fifth Avenue to the cheers of thousands of paradegoers.

“Eight thousand New York City residents are currently fighting overseas,” Mayor Bloomberg said yesterday.

“Forty thousand veterans live in New York City. Fifty-five New York City veterans have given their lives in the Iraq and Afghanistan wars. There’s nothing we can say to bring them back. God help us if we forget.”With Post Wire Services